From: Johan Hovold <johan@kernel.org>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Masahiro Yamada" <masahiroy@kernel.org>,
"Michal Marek" <michal.lkml@markovi.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>, Rob Herring <robh@kernel.org>,
linux-kernel@vger.kernel.org, kernel@pengutronix.de,
kbuild test robot <lkp@intel.com>,
linux-kbuild@vger.kernel.org
Subject: kbuild obj-m directory descend (was: Re: [PATCH] serdev: fix builds with CONFIG_SERIAL_DEV_BUS=m)
Date: Wed, 18 Dec 2019 18:23:53 +0100 [thread overview]
Message-ID: <20191218172353.GO22665@localhost> (raw)
In-Reply-To: <20191218083842.14882-1-u.kleine-koenig@pengutronix.de>
On Wed, Dec 18, 2019 at 09:38:42AM +0100, Uwe Kleine-König wrote:
> Commit 54edb425346a ("serdev: simplify Makefile") broke builds with
> serdev configured as module. I don't understand it completely yet, but
> it seems that
>
> obj-$(CONFIG_SERIAL_DEV_BUS) += serdev/
>
> in drivers/tty/Makefile with CONFIG_SERIAL_DEV_BUS=m doesn't result in
> code that is added using obj-y in drivers/tty/serdev/Makefile being
> compiled. So instead of dropping $(CONFIG_SERIAL_DEV_BUS) in serdev's
> Makefile, drop it in drivers/tty/Makefile.
I was just looking into this when you commented on this off-list.
The offending patch is broken since it effectively makes
CONFIG_SERIAL_DEV_BUS bool (built-in or disabled), but for some reason
those symbols do not end up in vmlinux (despite being compiled) when you
add a built-in object goal under a directory that was entered using
obj-m.
That seems like a bug to me and contradicts the kbuild documentation
(3.6):
Example:
#fs/Makefile
obj-$(CONFIG_EXT2_FS) += ext2/
If CONFIG_EXT2_FS is set to either ‘y’ (built-in) or ‘m’
(modular) the corresponding obj- variable will be set, and
kbuild will descend down in the ext2 directory. Kbuild only uses
this information to decide that it needs to visit the directory,
it is the Makefile in the subdirectory that specifies what is
modular and what is built-in.
I tried adding other targets to obj-y directly and they are also are not
included, seemingly since the directory was entered using obj-m.
Masahiro or Michal, can you shed some light?
Johan
next prev parent reply other threads:[~2019-12-18 17:24 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <201912181000.82Z7czbN%lkp@intel.com>
2019-12-18 8:38 ` [PATCH] serdev: fix builds with CONFIG_SERIAL_DEV_BUS=m Uwe Kleine-König
2019-12-18 9:06 ` Johan Hovold
2019-12-18 9:29 ` Uwe Kleine-König
2019-12-18 9:38 ` Johan Hovold
2019-12-18 10:39 ` Uwe Kleine-König
2019-12-18 12:51 ` Johan Hovold
2019-12-18 17:23 ` Johan Hovold [this message]
2019-12-19 2:00 ` kbuild obj-m directory descend (was: Re: [PATCH] serdev: fix builds with CONFIG_SERIAL_DEV_BUS=m) Masahiro Yamada
2019-12-19 8:18 ` Johan Hovold
2019-12-19 8:55 ` Masahiro Yamada
2019-12-19 9:49 ` Johan Hovold
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191218172353.GO22665@localhost \
--to=johan@kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=jslaby@suse.com \
--cc=kernel@pengutronix.de \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lkp@intel.com \
--cc=masahiroy@kernel.org \
--cc=michal.lkml@markovi.net \
--cc=robh@kernel.org \
--cc=u.kleine-koenig@pengutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).